1. Field of the Invention
The present invention relates to a remote control system for remotely controlling a biped (two-legged) locomotion robot.
2. Description of the Prior Art
There has heretofore been known in the art a remote control system for remotely controlling a robot to operate with a robot manipulator such as a joystick.
For controlling a biped locomotion robot to walk forward, the operator operates the robot manipulator in a direction corresponding to the forward side of the robot. The stride, walking stride, etc. of the robot are commanded by the amount of movement of the robot manipulator as it is operated by the operator.
With the known remote control system, since the movement of each of the legs as the biped locomotion robot walks, i.e., as the legs are alternately landed on the floor and lifted off the floor, is of a pattern which is entirely different from the pattern of movement of the robot manipulator, the operator cannot easily obtain a feel of the actual movement of the robot legs. For example, when the operator commands the stride or walking speed of the biped locomotion robot with the amount of movement of the robot manipulator, the stride or walking speed which is actually while perceptively recognizing the movement of the legs of the robot, and also to move the robot in a wide range under various different environmental conditions.
To achieve the above object, there is provided in accordance with the present invention a remote control system for remotely controlling a biped locomotion robot as manipulated by an operator, comprising an upper body support mechanism for supporting an upper body of the operator while allowing the operator to move feet thereof, foot operation state detecting means for detecting operation states of the feet of the operator whose upper body is supported by the upper body support mechanism, and leg operation commanding means for applying leg operation commands to the biped locomotion robot depending on the operation states of the feet of the operator as detected by the foot operation state detecting means.
For operating the legs of the biped locomotion robot, the operator supports its own upper body on the upper body support mechanism, and moves the feet in a pattern, e.g., a walking pattern, in which the operator wants to move the legs of the biped locomotion robot. At this time, the foot operation state detecting means detects an operation state of each of the feet of the operator, e.g., the operation of each foot corresponding to the lifting of each leg of the biped locomotion robot from a floor, the operation of each foot corresponding to the landing of each leg of the biped locomotion robot on a floor, the position or orienta-achieved may be greater or smaller than the operator has expected, but the operator cannot perceptively recognize such an error from the amount of movement of the robot manipulator.
Therefore, the operator is required to be highly skilled to operate the robot manipulator in order to control the robot to operate exactly as intended by the operator.
Another tpye of remote control system has a master unit which is worn by the operator. For controlling the biped locomotion robot to walk with the master unit, the operator actually walks, and the master unit delivers a command representing the walking movement of the operator to the biped locomotion robot.
The remote control system requires that the master unit be equipped with a facility which provides the same environment as the environment in which the robot operates, i.e., a floor on which the robot moves and other structures surrounding the robot. Because of limitations imposed by such a facility, the remote control system fails to move the robot in a wide range under various different environmental conditions.
It is therefore an object of the present invention to provide a remote control system for remotely controlling a biped locomotion robot with a robot manipulator operated by the operator, the remote control system allowing the operator to move legs of the robot reliably as desired locomotion of each foot from time to time, or a rate of change thereof. Depending on the detected operation states of the feet of the operator, the leg operation commanding means applies leg operation commands to the biped locomotion robot. The legs of the biped locomotion robot are operated on the basis of the applied leg operation commands.
Therefore, the operator can manipulate the legs of the biped locomotion robot with the movement of its own feet, and can recognize the operation of the legs of the biped locomotion robot with the movement of its own feet. Since the operator is able to operate the legs of the robot by moving its own feet while the upper body is being supported by the upper body support mechanism, the operator is not required to move in order to operate the robot. Thus, the operator can move the robot at will under given environment conditions for the robot simply by moving the feet in view of the environment conditions for the robot.
With the remote control system, the operator can perceptively recognize the movement of the legs of the robot based on the movement of its own feet, and hence can move the legs of the robot reliably as desired. The operator can also move the robot in a wide range under various environmental conditions.
The operation states of the feet of the operator include at least an operation state of each of the feet of the operator which corresponds to lifting of each leg of the biped locomotion robot from a floor, and an operation state of each of the feet of the operator which corresponds to landing of each leg of the biped locomotion robot on a floor.
Since the biped locomotion robot moves or walks by repeatedly lifting and landing its legs like human beings, the operation states of the feet of the operator which correspond to the lifting and the landing of the legs of the robot are detected, and leg operation commands based on the detected operation states are given to the robot for thereby walking the robot accurately according to the pattern of movement of the feet of the operator.
Preferably, the foot operation state detecting means comprises operator foot position/orientation detecting means for detecting a relative positional and/or orientational relationship between the feet of the operator in at least the operation state of each of the feet of the operator which corresponds to landing of each leg of the biped locomotion robot on the floor, and the leg operation commanding means comprises means for applying a command representing a landed position and/or orientation of the leg to be landed of the biped locomotion robot to the biped locomotion robot depending on the relative positional and/or orientational relationship between the feet of the operator as detected by the foot operation state detecting means.
The landed position and/or orientation of each leg to be landed of the biped locomotion robot is determined by the relative positional and/or orientational relationship between the feet of the operator in the operation state of each of the feet of the operator which corresponds to landing of each leg of the biped locomotion robot on the floor. Therefore, when the operator moves the foot corresponding to one of the legs to be landed of the robot while walking the robot, the operator adjusts as desired the relative positional and/or orientational relationship of the foot to the other foot, so that the operator is able to control the stride of the robot and the direction of walking of the robot in the same manner as the operator walks. The operator can operate the legs of the robot as desired with a feel of unison between the movement of the feet and the movement of the legs of the robot.
The remote control system further comprises a foot support mechanism for supporting the feet of the operator whose upper body is supported by the upper body support mechanism, the foot support mechanism being movable with the feet of the operator, actuator means for actuating the foot support mechanism, robot foot position/orientation detecting means for detecting a position and/or orientation of a foot of a leg of the biped locomotion robot with respect to an upper body of the biped locomotion robot when the leg of the biped locomotion robot is landed on the floor, and foot support mechanism control means for controlling the actuator means to equalize the position and/or orientation of the foot of the operator which corresponds to the landed leg of the biped locomotion robot with respect to the upper body of the operator, to a position and/or orientation which corresponds to the position and/or orientation, detected by the robot foot position/orientation detecting means, of the foot of the landed leg of the biped locomotion robot with respect to the upper body of the biped locomotion robot.
If the robot walks forward, for example, the leg that is landed (the supporting leg) moves backward with respect to the upper body of the robot. If the robot walks up steps, for example, the leg that is landed moves backward and downward with respect to the upper body of the robot. The foot support mechanism control means controls the actuator means to equalize the position and/or orientation of the foot of the operator which corresponds to the landed leg of the biped locomotion robot with respect to the upper body of the operator, to a position and/or orientation which corresponds to the position and/or orientation, detected by the robot foot position/orientation detecting means, of the foot of the landed leg of the biped locomotion robot with respect to the upper body of the biped locomotion robot. Thus, the foot of the operator corresponding to the landed leg of the robot moves with respect to the upper body of the operator in the same pattern as when the robot walks or walks up or down steps. Consequently, the operator can operate the legs of the robot as desired with a greater feel of unison between the movement of the feet and the movement of the legs of the robot.
Preferably, the foot support mechanism has foot acting force detecting means for detecting an acting force applied from each of the feet of the operator, and the foot support mechanism control means comprises means for controlling the actuator means to cause the foot support mechanism to follow movement of each of the feet of the operator based on the acting force detected by the foot acting force detecting means.
Even in the absence of any means for controlling the position and/or orientation of the foot of the operator corresponding to the landed leg of the robot with respect to the upper body of the operator, the remote control system preferably further comprises a foot support mechanism for supporting the feet of the operator whose upper body is supported by the upper body support mechanism, the foot support mechanism being movable with the feet of the operator, foot acting force detecting means for detecting an acting force applied from each of the feet of the operator, actuator means for actuating the foot support mechanism, and foot support mechanism control means for controlling the actuator means to cause the foot support mechanism to follow movement of each of the feet of the operator based on the acting force detected by the foot acting force detecting means.
Because an acting force applied from each foot of the operator to the foot support mechanism is detected, and the actuator means for actuating the foot support mechanism is controlled to cause the foot support mechanism to follow movement of each of the feet of the operator based on the detected acting force, the operator can move its own feet supported by the foot support mechanism freely without any substantial efforts, and hence can smoothly operate to move the legs of the robot as desired.
In order to cause the foot support mechanism to follow movement of each of the feet of the operator, the foot support mechanism control means comprises means for controlling the actuator means to move the foot support mechanism into a position and/or orientation to reduce a change in the acting force detected by the foot acting force detecting means.
The remote control system which basically comprises the upper body support mechanism, the foot operation state detecting means, and the leg operation commanding means is capable of detecting the operation states of the feet of the operator based on speeds or accelerations of the feet or acting forces applied from the feet to the foot support mechanism. However, the remote control system may be arranged as follows:
The remote control system may further comprise a rotatable ball for placing releasably thereon the feet of the operator whose upper body is supported by the upper body support mechanism, foot landing/lifting detecting means for detecting whether each of the feet of the operator is landed on or lifted off the ball, and ball rotation detecting means for detecting an angular displacement and/or a rotational direction of the ball when the ball is rotated by one of the feet of the operator after the other foot of the operator is lifted off the ball until the other foot is landed again on the ball, the foot operation state detecting means comprising means for producing detected data from the foot landing/lifting detecting means and detected data from the ball rotation detecting means as data indicative of the operation states of the feet of the operator.
The operator whose upper body is supported by the upper body support mechanism moves its feet alternately up and down with respect to the ball and rotates the ball with the foot held in contact with the ball, for thereby moving the feet in substantially the same pattern as when the operator is actually walking. The detected data (indicative of whether the feet are landed on or lifted off the ball) from the foot landing/lifting detecting means and the detected data (indicative of an angular displacement and/or rotational direction of the ball) from the ball rotation detecting means are representative of the operation states of the feet of the operator. The detected data from the foot landing/lifting detecting means and the detected data from the ball rotation detecting means are obtained as data indicative of the operation states of the feet of the operator, and leg operation commands are given to the biped locomotion robot depending on the operation states of the feet of the operator for thereby moving the legs of the biped locomotion robot in a pattern matching the movement of the feet of the operator.
More specifically, the leg operation commanding means comprises means for determining a leg of the biped locomotion robot which corresponds to the foot of the operator detected as being lifted off the ball by the foot landing/lifting detecting means, as a leg to be lifted off and landed on a floor, and applying a command indicative of a landed position and/or orientation for the leg depending on the angular displacement and/or the rotational direction of the ball as detected by the ball rotation detecting means, to the biped locomotion robot.
For moving the biped locomotion robot, the operator whose upper body is supported by the upper body support mechanism lifts one of the feet off the ball and then lowers the lifted foot onto the ball as if moving the robot with the movement of its legs. The operator moves the foot held in contact with the ball to rotate the ball such that a positional and/or orientational relationship between the feet of the operator at the time the lifted foot is landed onto the ball will correspond to a positional and/or orientational relationship between the feet of the legs of the robot when the lifted leg (swinging leg) of the robot is landed on the floor in a pattern in which the operator wants the robot to move the legs of the robot. For example, if the operator wants the robot to walk forward at a desired stride, then the operator alternately moves the feet up and down with respect to the ball. At this time, the operator moves the foot landed on the ball backward with respect to the foot lifted off the ball thereby to rotate the ball through an angular displacement that matches a stride to be achieved by a desired walking pattern for the robot (as the stride is greater, the angular displacement of the ball is greater). If the foot of the swinging leg of the robot is to be landed on the floor obliquely with respect to the foot of the supporting leg thereby to change the direction of movement of the robot when the robot is walking forward, then when the operator lands the lifted foot onto the ball, the operator orients the other foot held in contact with the ball to the foot to be landed onto the ball and rotates the ball obliquely.
While the operator is thus moving the feet relatively to the ball, the leg operation commanding means determines a leg of the biped locomotion robot which corresponds to the foot of the operator detected as being lifted off the ball by the foot landing/lifting detecting means, as a leg to be lifted off and landed on a floor, and applies a command indicative of a landed position and/or orientation for the leg depending on the angular displacement and/or the rotational direction of the ball as detected by the ball rotation detecting means, to the biped locomotion robot. Inasmuch as the angular displacement and/or the rotational direction of the ball, at this time, corresponds to the positional and/or orientational relationship between the feet of the legs of the robot when the swinging leg of the robot is landed on the floor in a pattern in which the operator wants the robot to move the legs of the robot, when a command indicative of a landed position and/or orientation for the leg depending on the angular displacement and/or the rotational direction of the ball is applied to the robot, the legs of the robot are moved in the same pattern as the operator moves the feet on the ball.
The remote control system further comprises a shoe adapted to be worn by each of the feet of the operator, the foot landing/lifting detecting means being mounted on the shoe. Therefore, the landing of each of the feet of the operator on the ball or the lifting of each of the feet of the operator off the ball can easily be detected using a contact switch or the like on the shoe. The angular displacement and/or the rotational direction of the ball can be detected by a mechanism similar to a track ball which is used to move a cursor on the display screen of a personal computer, for example.
Alternatively, the remote control system may further comprise a foot support for placing releasably thereon the feet of the operator whose upper body is supported by the upper body support mechanism, the feet of the operator being movable on the foot support, foot landing/lifting detecting means for detecting whether each of the feet of the operator is landed on or lifted off the foot support, and foot position/orientation detecting means for detecting a relative position/orientation of the feet of the operator on the foot support when one of the feet of the operator is lifted off the foot support and landed again on the foot support, the foot operation state detecting means comprising means for producing detected data from the foot landing/lifting detecting means and detected data from the foot position/orientation detecting means as data indicative of the operation states of the feet of the operator.
The operator whose upper body is supported by the upper body support mechanism moves its feet alternately up and down with respect to the foot support, and also moves the foot held in contact with the foot support, so that the feet can be moved in substantially the same pattern as when the operator is actually walking. The detected data (indicative of whether the feet are landed on or lifted off the foot support) from the foot landing/lifting detecting means and the detected data (indicative of a relative position and/or orientation of the feet of the operator on the foot support) from the foot position/orientation detecting means are representative of the operation states of the feet of the operator. The detected data from the foot landing/lifting detecting means and the detected data from the foot position/orientation detecting means are obtained as data indicative of the operation states of the feet of the operator, and leg operation commands are given to the biped locomotion robot depending on the operation states of the feet of the operator for thereby moving the legs of the biped locomotion robot in a pattern matching the movement of the feet of the operator.
More specifically, the leg operation commanding means comprises means for determining a leg of the biped locomotion robot which corresponds to the foot of the operator detected as being lifted off the foot support by the foot landing/lifting detecting means, as a leg to be lifted off and landed on a floor, and applying a command indicative of a landed position and/or orientation for the leg depending on the relative position/orientation of the feet of the operator on the foot support as detected by the foot position/orientation detecting means, to the biped locomotion robot.
For moving the biped locomotion robot, the operator whose upper body is supported by the upper body support mechanism lifts one of the feet off the foot support and then lowers the lifted foot onto the foot support as if moving the robot with the movement of its legs. The operator moves the foot held in contact with the foot support and also moves the lifted foot such that a positional and/or orientational relationship between the feet of the operator at the time the lifted foot is landed onto the foot support will correspond to a positional and/or orientational relationship between the feet of the legs of the robot when the lifted leg (swinging leg) of the robot is landed on the floor in a pattern in which the operator wants the robot to move the legs of the robot.
While the operator is thus moving the feet relatively to the foot support, the leg operation commanding means determines a leg of the biped locomotion robot which corresponds to the foot of the operator detected as being lifted off the foot support by the foot landing/lifting detecting means, as a leg to be lifted off and landed on a floor, and applies a command indicative of a landed position and/or orientation for the leg depending on the relative position and/or orientation of the feet of the operator on the foot support, as detected by the foot position/ orientation detecting means, to the biped locomotion robot. Inasmuch as the relative position and/or orientation of the feet of the operator, at this time, corresponds to the positional and/or orientational relationship between the feet of the legs of the robot when the swinging leg of the robot is landed on the floor in a pattern in which the operator wants the robot to move the legs of the robot, when a command indicative of a landed position and/or orientation for the leg depending on the relative position and/or orientation of the feet of the operator is applied to the robot, the legs of the robot are moved in the same pattern as the operator moves the feet on the foot support.
The foot landing/lifting detecting means and the foot position/orientation detecting means may be arranged as follows:
The remote control system may further comprise a distributed contact sensor mounted on an upper surface of the foot support, and the foot landing/lifting detecting means comprises means for detecting whether each of the feet of the operator is landed on or lifted off the foot support based on an output signal from the distributed contact sensor, and the foot position/orientation detecting means comprises means for detecting the relative position/orientation of the feet of the operator on the foot support based on an output signal from the distributed contact sensor.
The distributed contact sensor may comprise a matrix of sensor elements for detecting whether an object contacts the distributed contact sensor or not or for detecting a contact pressure applied by an object. With the distributed contact sensor mounted on the upper surface of the foot support, it is possible to recognize a position and orientation of the feet of the operator on the foot support based on the output signal from the distributed contact sensor. Based on the output signal from the distributed contact sensor, therefore, it is possible to detect whether each of the feet of the operator is landed on or lifted off the foot support, and also to detect a relative position and/or orientation of the feet of the operator on the foot support.
The above and other objects, features, and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example.